As usual, Giz has missed the bigger picture. The big advantage to rebreathers isn't stealth: it's bottom time. With a small tank, a diver can routinely hit upwards of four hours under the surface. Yes, if you were diving air, the you would not be able to descend below 20-30 feet on account of oxygen toxicity. But that's not a problem. Rebreathers are prohibitively expensive for most people. The Dive-Rite Optima I run set me back $7000 dollars. I also run it with trimix. I live in Gainesville, FL, which is right at the heart of the world-capital of cave diving, so the longer I have on the bottom, the better.

The reason I dropped so much money on the setup was that I was running low-pressure steel 140s, which together with my backplate and wing, weighed somewhere in the range of 150 pounds. I was only getting about two hours of bottom time. With my Optima, I get double that, with a setup that only weighs about as much as double aluminum 80s, somewhere in the range of sixty pounds. Poseidon is OK, but they're very expensive, and frankly, not as good as Dive-Rite. Basically, if you're in the market for tech diving gear, look at DiveRite.

If people have questions about why one would REALLY want to use a closed-system setup, check out this link:

[www.diveriteexpress.com]

SonOfMagicFact

You are almost guaranteed a longer "surface interval" due to the increased nitrogen you will still take in. What are we saving here that refilling a regular old tank (topside) and going down again could not do better?

Now if the intent is for cave diving and we don't want to add bubbles to the top of the cave, I can accept that. Otherwise... not so much.

axiomatic

Do they make a Nitrox setup? Then I would buy one for my open water deep dives.

dss902

Actually, I don't see this being great for deep dives past a certain point. The nitrogen would be a concern yes, but it seems to me that as you breathe and it recycles oxygen from your CO2, it will start becoming a richer and richer oxygen mix, and oxygen in high ratios under pressure is toxic. That's why you have to observe max operating depths when you breathe nitrox.

singlecoilpickup

I hear the battery's non replaceable. *scoff*

workingonyourinvoice

The auto gas mix is a nice feature for deep diving...us 100ft'ers always endup wishing we could go just another few feet.

kir

Stick one of these on the exhaust of your car for zero emissions! There ya go, Al Gore can rest easy tonight!

djeror

@mrxcel: That's because most recreational divers just have a beginners open water certification and are not suppose to dive below 100 ft. You're not going to be down that far diving at any resort either.

baltwade

@Lukewpnunn:

More sophisticated rebreathers (like this one probably is, since Poseidon is pretty high-end) constantly alter the gas mix to maintain the best nitrogen/Oxygen mix for a given depth. The original article says that it doesn't protect you from the bends, but I'd bet its advanced enough to make deeper/longer dives much more efficiently than air or Nitrox (or Heliox for that matter).

UGA

@Munch420s: The wet suit would keep those in.

Git Em SteveDave

@Buehler: Wow. Thank you! I AAAAAM IRONNNN MAAAAN!

SeattleTed

@baltwade:
It all depends what you are diving for... trimix for recreational divers is not the best way to dive... I'd like to see you ask for Trimix at any diving resort... 80% would be like TriWhat?

mrxcel

"Diving is fun until your oxygen tank runs out and you die"

Who dives with an oxygen tank? Last time I dove, it was just compressed air...

rancemuhamitz

@DeadWriter: That video is awesome. effin' cephalopods.

pushlatency

@Lukewpnunn: As long as you you don't dive deeper than about 100 feet nitrogen levels shouldn't be a problem no matter how long you're down. If you're going to dive deeper than 100 feet you should probably be using a trimix anyway. Some industrial/construction divers have stayed at pressure for weeks at a time with no problems.

baltwade

maybe they can do it for a whole space suit.

yeeeuuuch.

flyboy

Who needs stealth? I just go real fast because I am SuperMan:

Your results:
You are Superman
Superman
75%
Green Lantern
75%
Spider-Man
70%
Iron Man
70%
The Flash
55%
Hulk
55%

You are mild-mannered, good,
strong and you love to help others.



Click here to take the Superhero Personality Test

Sorry, I just found that somewhere and HAD to use it :)

Buehler

@baltwade: I just read the brochure. It's very very nice and would be a great addition to my non-existent dive gear collection.

But no, there isn't any fundamental difference here to the rebreathers that have been in use for quite some time, (I think it might be more then a decade). Basically, you don't use all of the oxygen you breathe in, so it recycles the unused amount you exhale.

Giz, you may want to revise the "recycling your carbon dioxide exhaust and turning it into breathable oxygen" line in the post as it's a bit misleading. After reading that I started wildly speculating that this rebreather somehow came equipped with juiced-up bonzai trees that convert your CO2 into O2.

pushlatency

Perfect for mouth breathers everywhere.

GiltProto

@Noobs-R-Us: Made for the Navy Seals or to feed our Cthulhuesk friends .

Diver Vs Octopus - from the Metacafe

DeadWriter

@baltwade: I was just thinking the same thing. Maybe it's just smaller.

TheCyberBob

I read that quickly as... "D r iving is fun until your oxygen tank runs out and you die", wondering what kind of pollution you have there! Shizza!

ANoel

Only good for a first deep dive or repetetive shallow dives otherwise nitrogen levels will become the limit of your dive time not how much air you have left!

Lukewpnunn

I would still be giving my location away with bubbles

Munch420s

Designed for the SEALS.

Noobs-R-Us

So how is this different from the re-breathers that have been around for over a decade now? Maybe I should read the article.

baltwade

This works great until creatures in that unknown cave in a random former soviet republic attack you, your tank is damaged, ruptures, explodes, then caves the tunnel in on your friends so that they are forced to go deeper into the cave to escape.

Xavoc

sure, u may not die due to drowning, but with that battery strapped to ur back theres definitly other ways to die.

Sheemo44

The other cool thing about rebreathers is that your buoyancy doesn't change as you breathe in and out, because the air bladder (in a closed loop system) holds the same volume of air. This is possibly the most annoying thing for a less experienced diver trying to look at stuff on the floor.

Jered

Isn't this mainly different in that traditional rebreathers are a chemical scrub, while this appears to be some sort of electrical scrubber? Don't know a terrible lot about them though as I'm only BOW.

1roll20s

@The Lab: Oh, and in case it wasn't obvious, that last post was in response to you.

SonOfMagicFact

I've got one BIG-ASS wing. 102 pounds of lift. I've got a much smaller one for my rebreather, as that's way overkill. ^_^

SonOfMagicFact

@SonOfMagicFact: Double 140s? holy shit... It is amazing you could, you know, swim.

The Lab

@allenjnl: Thank you for pointing out that fact. I had forgotten to mention the fact that traditionally, most rebreathers ran on pure oxygen, which has the toxicity figures I mentioned. You're absolutely right: on air, the O2 becomes toxic at around 200 ft. I concede my point on that one. In response to your other topic, I've been VERY anxious to hit my first reef dive, as I've been incredibly busy with school. I'm traveling down to Jupiter in two weeks, so hopefully that will be as life-altering as I hope it to be. I'm sorry if I came off a little bit "preachy," but in tech-diving, it's very difficult not to become more than a little opinionated about this stuff. :3 Again, thanks a lot for pointing out my errors.

SonOfMagicFact

@SonOfMagicFact: You know, if you're actually a cave diver you should hit the books for a while. The max depth on air before you reach oxygen toxicity is about 205 ft. If the Posiedon system actively manages the PO2 you can safely go deeper. Presumably it would also take into account the nitrogen fraction when computing your deco time/N2 tissue load and give you accurate deco info on the display. I agree that long bottom time is a great advantage, especially when cave diving, but the stealth aspect is significant as well. If you've taken your rebreather on a typical reef dive, you'd be stunned how much closer you can get to the sea life. In Florida, it is illegal to spearfish with a rebreather for this reason. I think the biggest pain in the ass with most rebreathers is scrubber maintenance and lack of active o2 controls on the affordable units. This looks like they've tried to address those issues. I'm interested enough to go to my dive shop and learn some more. Just sayin'...

allenjnl

The Mk VI has some very interesting (revolutionary?) things going for it (e.g., no more 3-way voting logic), but it's pioneering the "recreational" rebreather market and frankly, a lot of RB divers are scared s-less over the fact that it's fully electronic (ECCR).

I'd let someone else be the guinea pig for this one.

El Guano

Oh, and in response to the nitrogen question: yes, it is an issue. That's why we have a decompression stop along the way, where we breathe nitrox with very high concentrations of oxygen, upwards of 50%. That being said, we still have to be careful over the next few days, as it takes anywhere from 18 to 36 hours for the nitrogen micro-bubbles to fully dissipate.

SonOfMagicFact

"Poseidon is OK, but they're very expensive, and frankly, not as good as Dive-Rite."

Bollocks. I suggest you carefully review Poseidon's history and their past and current products. Their gear is among the most sophisticated, capable, and reliable in the world, and their pricing reflects that. As for DiveRite, they don't even make a regulator. The regs they sell are all rebadged models made by European companies like Beuchat and...(drum roll)...Poseidon.

As it happens, the MK VI Discovery was actually designed by Bill Stone, et al, in conjunction with Poseidon's engineers. Thus, it's really a Cis-Lunar based unit, designed by the Cis-Lunar guys, and manufactured by Poseidon. Hence the progression from Mark V to Mark VI. Disparage Poseidon all you want, but the name Cis-Lunar is synonymous with "the ultimate" among many rebreather divers and the new Discovery unit will probably be recognized as an important achievement in the history of dive technology.

If people REALLY want to know how the MK VI Discovery works, read Bill Stone's white paper on it at --> [www.poseidon.se]

Znaught

@ SonOfMagicFact
Say hello to Bill @ Cave Excursions for me, I rent tanks from him every time I hit Cave Country.

@allenjnl: 200 feet on air and you would be lucky to remember they dive given the level of nitrogen narcosis, regardless of the ox-tox risk.

@ 1roll20s No, this has a chemical scrubber. Let me know when they invent an electronic version of a scrubber for diving purposes.

Finally, the interesting thing about this rebreather is the lack of controls, you basically ride this thing on auto pilot. This is an electronically controlled CCR that it's being marketed towards the Club Med set, not the tech diver.

I'll get a rebreather in the future but I'll get one with slightly more control, like a manual rEvo or a KISS rebreather.

breals

real genius?

toyotaboy

@Znaught: You're right. I was far too quick in part of my judgment. Poseidon is, in may respects, better than Dive Rite. However, they are more expensive than many other expensive things combined. I was recently looking at their harness, which is infinitely cool in its complete adjustability, but also infinitely expensive at 800 dollars just for the harness, without a backplate or wing. So yes, Poseidon, I would have to say, is better. You also pay a major premium for that quality.

SonOfMagicFact

@Xavoc: Boy I hate when that happens. >:)

Seriously, though, if I could drop the cash for a rebreather I'd do it. More bottom time. Less bubbles to upset that fish you want to photograph. All good :)

ken_usa

@baltwade, Commercial divers do not use trimix, at least not in the Gulf of Mexico. We use a Helium Oxygen mix, especialy for saturation dives which the diver will typically stay at pressure for 30 days. As for the rebreather itself it is a powerd version of a rebreather, more stuff to get corroded by salt water and break.

insane_diver

To correct the article (and the various comments): this is not (and nor are any other diving tanks) straight oxygen you are breathing: pure oxygen is toxic at relatively shallow depths.

Rebreathers might have an oxygen tank, but that's because they are putting back the O2 taken out by your lungs (and scrubbing CO2).

You're breathing plain old air with most scuba tanks unless you're going very deep and then start mucking around with mixtures of various gasses.

NathanLee

They ripped this off from the movie Real Genius.

Mr.SithNinja

@SonOfMagicFact: Are you referring to 'The Platform'? The MSRP is $800?!? That IS expensive. It looks like a great product, but I find it very difficult to justify such a price, even if it's a Poseidon product. Photos of The Platform reveal a carbon fibre finish, but whether it is really made of carbon fibre or just a faux finish, I can't tell. However, considering its exorbitant price, it at least should be made of aerospace spec CFRP, or even inconel!

Dive Rite does make quality gear too, but is generally more affordable. It also helps that it's a U.S. based company, so the plummeting value of the dollar won't affect their pricing like European goods are. The best thing about Dive Rite though is that they'll sell parts kits to end users so that they can service their own gear. That's pretty damned cool! You'll save allot of money servicing your gear! In fact, if you want a Poseidon regulator, but can't afford Poseidon's prices or the maintenance/service costs, then you can buy the 'new' Dive Rite Jetstream (which is a Poseidon Xstream 1st stage mated to a Jetstream 2nd stage) and pick up the parts kits as you need them! I'll probably buy one myself.

Oh, and FYI, Poseidon's Cis-Lunar Mark VI Discovery (what a bloody long name!) uses two Xstream 1st stages for its cylinders, so it's top-of-the-line kit. Now if only it didn't have over-the-shoulder counterlungs...

Znaught